System and method to program air conditioner modules

ABSTRACT

A system to program microcomputers associated with a plurality of bus rooftop air conditioners comprises a plurality of air conditioner modules located on a bus rooftop. Each air conditioner module includes a microcomputer. Each microcomputer is connected to a CAN (computer area network) bus connection, and the CAN bus is common to each microcomputer. The system also includes a programming device that is communicatively coupled to at least one of the microcomputers of one of the plurality of air conditioner modules, wherein the programming device transfers a software update to the at least one of the microcomputers followed by the at least one of the microcomputers transferring the software update to each of the microcomputers in the of air conditioner modules located on a bus rooftop. A method for programming a plurality of microcomputers contained within a plurality of bus air conditioning modules is also presented.

FIELD OF THE INVENTION

This invention relates generally to programming a plurality ofmicrocomputers and more specifically to programming a plurality ofmicrocomputers associated with bus rooftop air conditioner modules.

BACKGROUND OF THE INVENTION

The modern trend for air conditioning buses used in transportation is tolocate air conditioner modules on the roof of the bus. Each airconditioner module typically includes at least one microcomputer used tosupervise and control the functions of the air conditioning module. Themicrocomputer runs a computer program generally installed at the time ofair conditioner module production.

Another trend in microcomputer based apparatus is periodic revision ofthe microcomputer software in a post production environment. Thesoftware update might be performed to correct a flaw in the software, toadapt the microcomputer based apparatus to a new configuration, orsimply to install the latest version of the appropriate code. Typicallysuch updates are done from a personal computer via a cable connectedfrom the personal computer to the microcomputer based apparatus.

In the case of bus roof top air conditioner modules, such manualconnections for microcomputer re-programming can be problematic. Mostimportantly, there is some physical danger to the technician involvingclimbing to the roof and working at a significant height above atypically hard surface, such as a concrete bus garage floor. Time isalso a factor since it is now common for larger buses to have four ormore rooftop air conditioner modules and the microcomputer in eachmodule needs to be updated. Another problem is that if a technician isdistracted, it is possible that one or more of the rooftop modules isnot updated and is left operating on a different version of themicrocomputer code.

What is needed is a system and method to ensure that all microcomputersassociated with bus rooftop air conditioner modules are programmed withthe same software update without requiring a technician to climb on thebus rooftop.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a system to programmicrocomputers associated with a plurality of bus rooftop airconditioners comprises a plurality of air conditioner modules located ona bus rooftop. Each air conditioner module includes a microcomputer.Each microcomputer is connected to a CAN (computer area network) busconnection, and the CAN bus is common to each microcomputer. The systemalso includes a programming device that is communicatively coupled to atleast one of the microcomputers of one of the plurality of airconditioner modules, wherein the programming device transfers a softwareupdate to the at least one of the microcomputers followed by the atleast one of the microcomputers transferring the software update to eachof the microcomputers in the of air conditioner modules located on a busrooftop.

In accordance with another aspect of the invention, a method forprogramming a plurality of microcomputers contained within a pluralityof bus air conditioning modules comprising the steps of: providing aplurality of bus air conditioning modules having air conditioning modulemicrocomputers on a microcomputer network; providing a programmingdevice; connecting the programming device to one of the microcomputers;establishing a communications link between the programming device andthe one of the microcomputers; programming the one of themicrocomputers; commanding the one of the microcomputers to broadcastthe program to the other microcomputers on the microcomputer network;and commanding all of the microcomputers to run the program.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of these and objects of the invention,reference will be made to the following detailed description of theinvention which is to be read in connection with the accompanyingdrawing, where:

FIG. 1 shows a block diagram one embodiment of a system according to theinvention for programming a plurality of microcomputers situated on therooftop of a bus;

FIG. 2A and FIG. 2B show two exemplary layouts for mounting airconditioning modules 201 on the rooftop of a bus; and

FIG. 3 shows one embodiment of steps useful for performing the inventivemethod.

The drawings are not necessarily to scale, emphasis instead generallybeing placed upon illustrating the principles of the invention. In thedrawings, like numerals are used to indicate like parts throughout thevarious views.

DETAILED DESCRIPTION OF THE INVENTION

Definitions: A microcomputer is defined herein as synonymous with amicrocontroller, microprocessor, and a DSP chip. Moreover, amicrocomputer can also be any integrated device that can run programcode in software or firmware, including a field programmable gate arrayprogrammed to perform microprocessor type functions. A programmingdevice can be a computer that is programmed to perform the functions ofa programmer for programming microcomputers. Typically such a computercan be a hand held computer, a laptop computer, or a desktop computersituated in the vicinity of the microcomputer to be programmed. Theprogramming device can also be a special purpose, limited use computer,dedicated to programming tasks.

FIG. 1 shows a block diagram of one embodiment of the inventive systemfor programming a plurality of microcomputers 101 and 102 some or all ofwhich can be situated on the rooftop of a bus. Programming device 103can be electrically connected to a microcomputer 101, typically via aserial data link 105. The connection can be any suitable electricalconnection that can support the transfer of digital data betweenprogramming device 103 and microcomputer 101. Microcomputer 101 can alsobe communicatively coupled one or more microcomputers 102 via amicrocomputer bus 104. Microcomputer 101 is typically of the same typeas microcomputers 102, and microcomputer 101 is so labeled only toidentify a specific one of the microcomputers as connected toprogramming device 103 via serial data link 105. Typically, any of themicrocomputers 102 can equally take the place of microcomputer 101, withan appropriate serial data link 105 connected to that microcomputer,such as any of the microcomputers 102.

FIG. 2A and FIG. 2B show two exemplary layouts for mounting airconditioning modules 201 on the rooftop of a bus 202. Such airconditioning modules are available from the Carrier Corporation ofSyracuse, N.Y. Similar air conditioning modules were described in moredetail in U.S. Pat. No. 6,925,826 B2, “Modular Bus Air ConditioningSystem”, issued to Hille, et al. and is hereby incorporated by referencein its entirety. These layouts are merely illustrative of the modules,and not intended to be limiting as to the number of modules or positionof each module. For example, a module 201 can also be mounted on therear of a bus, usually in the vicinity of a rear window. A connection toserial data link 105 can be provided in any convenient location, such aswithin an access door or compartment on the inside or outside of bus 202(not shown in FIG. 2A or FIG. 2B). The connection to serial data link105 can be in the form of an electrical connector on a surface or wall,typically in a protected location. Or, the connection to serial datalink 105 can also be in the form of a “pig tail”, a cable terminatedwith a suitable connector. Such a connector can accept a cable fromprogrammer 103 or a long enough pig tail can plug directly into aprogrammer 103. The cable that provides serial data link 105 can thus beadvantageously located such that programming device 103 can be situatedin any user accessible location, such as in a location where atechnician can easily access the programming device 103 without climbingon or near the roof of the bus. Suitable locations for positioningprogramming device 103 include bus 202 surfaces at a level that allowfor easy access by a technician standing on the ground outside of thebus 202 or while standing or, preferably sitting, within the bus 202.

FIG. 3 shows one embodiment of steps to perform the inventive method. InSTEP A, programming device 103 is connected to a microcomputer 101. InSTEP B, programming device 103 establishes communications with themicrocomputer 101. In STEP C, programming device 103 programsmicrocomputer 101 by transferring a program to it in a digital datatransmission. In STEP D, programming device 103 commands microcomputer101 to broadcast the program to the other microcomputers onmicrocomputer bus 104. And finally in STEP E, programming device 103commands all microcomputers to run the program. This last step cantypically be performed by a direct command from programming device 103to microcomputer 101 for relay of the command to all othermicrocomputers across microcomputer bus 104. Step E can also beperformed by causing a system reset of all microcomputers onmicrocomputer bus 104.

Suitable serial protocols for serial data link 105 include RS-232,RS-485, USB, as well as a data bus connection similar to microcomputerbus 104. Any suitable controller area network (CAN) can be used formicrocomputer bus 104.

A portion of the inventive system was tested using a Dell laptopcomputer as the programming device. A preliminary Carrier Corporationmarathon controller, comprising a DSP chip manufactured by the MotorolaCorporation of Tucson. Ariz., was used as microcomputer 101. It iscontemplated that a complete a system of air conditioning modulesincluding microcomputers on a CAN bus can perform the remainder of thesystem and method as described herein.

Advantageous aspects of the inventive system and method include safetyand reliability. A technician no longer needs to climb or work inawkward and potentially dangerous positions since all of themicrocomputers in the air conditioning modules on a bus can beprogrammed from a single safe location. Reliability of the bus airconditioning system is also enhanced, since there is little risk offorgetting to re-program or update the software in one or more of agroup of air conditioning modules. This ensures that the microcomputersin all of the air conditioning modules on a bus will be running the sameversion of code.

While the present invention has been particularly shown and describedwith reference to the preferred mode as illustrated in the drawing, itwill be understood by one skilled in the art that various changes indetail may be effected therein without departing from the spirit andscope of the invention as defined by the claims.

1. A system to program microcomputers associated with a plurality of bus rooftop air conditioners comprising: a plurality of air conditioner modules located on a bus rooftop, each air conditioner module including a microcomputer, each microcomputer connected to a CAN (computer area network) bus connection, the CAN bus common to each microcomputer; and a programming device communicatively coupled to at least one of the microcomputers of one of the plurality of air conditioner modules, wherein said programming device transfers a software update to said at least one of the microcomputers followed by said at least one of the microcomputers transferring said software update to each of the microcomputers in the of air conditioner modules located on a bus rooftop.
 2. The system of claim 1, wherein said programming device is a hand held programmer.
 3. The system of claim 1, wherein said programming device is a personal computer.
 4. The system of claim 3, wherein said personal computer is a laptop computer.
 5. The system of claim 1, wherein said programming device is communicatively coupled via a serial bus.
 6. The system of claim 5, wherein said serial bus is an RS-232 bus.
 7. The system of claim 5, wherein said serial bus is a USB bus.
 8. The system of claim 5, wherein said serial bus comprises a direct connection to the CAN bus.
 9. A method for programming a plurality of microcomputers contained within a plurality of bus air conditioning modules comprising the steps of: providing a plurality of bus air conditioning modules having air conditioning module microcomputers on a microcomputer network; providing a programming device; connecting the programming device to one of the microcomputers; establishing a communications link between the programming device and the one of the microcomputers; programming the one of the microcomputers; commanding the one of the microcomputers to broadcast the program to the other microcomputers on the microcomputer network; and commanding all of the microcomputers to run the program. 